1. Field of the Invention
The present invention relates to a component having a through-contact and a method for manufacturing a component having a through-contact.
2. Description of the Related Art
Electrical contact structures, which extend through a substrate or a subarea of a substrate, are known in various embodiments. Such contact structures, also known as vias (“vertical interconnect access”) or through-contacts, are becoming increasingly important because they facilitate the creation of space-saving components. A plurality of components may also be situated vertically one above the other and connected electrically by corresponding through-contacts, so that configurations having small (lateral) dimensions may be implemented.
Known methods for manufacturing a through-contact are based on insulating a substrate area of an electrically conductive substrate, which is to function as a “printed conductor,” from the surrounding substrate material. For this purpose, a trench etching method (“trenching”) is performed to create a trench structure, usually having a high aspect ratio, surrounding the substrate area. The corresponding substrate area is also suspended by insulating elements on a top side. On one hand, the trench structure should be sealed, and on the other hand, the smoothest possible surface should be provided. Sealing the trench structure helps to prevent unwanted or undefined introduction of material, which might have a deleterious effect on the insulation properties of the trench or the reliability of the through-contact. The smooth structure enables or facilitates performing the subsequent method steps, for example, CMOS (complementary metal oxide semiconductor) processes and MEMS (microelectromechanical system) processes.
In a known method, a trench structure is created, having a predefined, readily opening geometry which is subsequently filled with, for example, an oxide layer for insulation and a filling material, for example, polysilicon. A planarization process is performed next to smooth the surface. However, complete filling of the trench and performing the planarization process are relatively complex and difficult to control due to the predefined shape of the trench, which is adjusted relatively accurately.
Another known method includes producing a relatively narrow trench structure, which is sealed near the surface by depositing an oxide layer. According to one variant of the method, it is provided that, in order to create the sealing point as deep as possible, a first oxide is deposited first and is etched back anisotropically and then a second oxide is deposited. In addition, a planarization step may be provided to smooth the oxide seal. This method is associated with a relatively great effort, and it also cannot be used for some applications. On one hand, the effort increases drastically with an increase in width of the trench to be sealed, while on the other hand, a trench structure as narrow and, at the same time, as deep as desired cannot be produced.